Abstract
The Kinetic Metallization (KM) process allows the coating and dimensional restoration of interior diameter (ID) surfaces. It is a low temperature, low pressure, solid-state deposition process that is compliant with the recent MIL-STD-3021 cold spray materials deposition standard. The unique attribute of preheating powder particles to enhance ductility within the Kinetic Metallization process allows for high quality coating deposition onto the inner diameter of small-bore components using very short sonic nozzles. Inovati has developed a KM ID Spray Gun that can deposit a coating normal to the surface of the bore down to interior diameter sizes of 80-mm, with depth-to-diameter ratios exceeding 10-to-1. These ID deposition guns, when used with KM systems, can deposit the full range of coatings including structural aluminum alloys for rebuilding damaged forgings, superalloys for corrosion and/or oxidation protection, and hard-phase carbide coatings for wear resistance. This paper presents a case study for rebuilding of damaged 7075-Al forged landing gear outer cylinders requiring ID coating repairs of 0.020-0.030 inches in thickness. A separate study focuses on tungsten-carbide cobalt (WC-17Co) on steel liners and actuating cylinders for replacing hard chrome coatings and repairing worn cylinder bores.
